What is the 30% rule for rent?

A widely used guideline says rent should be no more than 30% of your income. Spending more than that can leave too little for other essentials and saving. This calculator defaults to 30% but lets you raise or lower it, because the right ceiling depends on your city, lifestyle and other commitments.

How is the recommended maximum rent worked out?

The tool computes two ceilings and takes the lower one. The first is the percentage rule — your chosen percent of income. The second is a cashflow ceiling — your spendable income minus all listed expenses minus your savings target. Whichever is smaller becomes the recommendation, so it never suggests a rent your real budget cannot support.

Should I apply the rule to gross or net income?

Both are defensible. Landlords and letting agents usually screen against gross (pre-tax) income, so a gross basis matches how they assess you. Net (take-home) income is the more realistic measure of what you actually have to spend, so it tends to give a safer ceiling. Switch the basis at the top to compare the two.

Why does adding expenses lower my recommended rent?

A simple percentage rule ignores your existing commitments. By subtracting loans, utilities, food, transport and a savings target from your spendable income, the cashflow ceiling reflects what is genuinely left for rent. When your commitments are high, this cashflow figure becomes the binding limit and the recommendation drops below the percentage rule.

What rent-to-income ratio is considered safe?

As a rough guide, at or below 30% of spendable income is comfortable, 30 to 40% is stretched, and above 40% is risky because small income shocks can push you into arrears. The tool colour-codes your recommended ratio into these three bands so you can see where you stand at a glance.

Is my income data private?

Completely. The calculator is privacy-first — every figure is processed in your browser, auto-saved only to your own device, and never transmitted to or stored on any server.

Rent Affordability Calculator

How much rent can you comfortably afford? This calculator starts from your income, applies an adjustable rent rule (the classic 30% by default), subtracts your real monthly expenses and a savings target, and returns a recommended maximum rent you can actually sustain. It is built for the moment before a flat hunt or a lease signing, when a single percentage is not enough and you want a number that respects your existing commitments. Every figure is currency-agnostic — pick your currency or use whichever fits your market — and nothing ever leaves your browser.

How it works

Most rent guidance stops at one number — “spend 30% of your income”. That is a useful anchor, but it ignores the loans, bills and savings goals that already claim part of your pay. This tool models both views and is deliberately conservative:

Percentage ceiling = your chosen rule percent applied to income. You decide whether that income is net take-home or gross pre-tax.
Cashflow ceiling = spendable income (net monthly plus any other monthly income) minus the sum of your listed commitments minus your savings target.
Recommended maximum rent = the lower of those two ceilings, so the result is never higher than your real budget allows.
Rent-to-income ratio = recommended rent divided by spendable income, colour-coded comfortable, stretched or risky.

The tool also tells you which ceiling is binding — the percentage rule or your cashflow — so you know whether the limiting factor is the guideline or your actual outgoings. A doughnut chart splits your spendable income into recommended rent, other expenses, savings and the remaining cushion.

Example

Suppose your net monthly income is 2,800 with no other income, you keep the rule at 30%, you save 10%, and your monthly commitments are 200 debt, 250 utilities, 350 food and 150 transport (1,000 total).

Percentage ceiling = 2,800 times 30% = 840
Savings set aside = 2,800 times 10% = 280
Cashflow ceiling = 2,800 minus 1,000 expenses minus 280 savings = 1,520
Recommended maximum rent = the lower of 840 and 1,520 = 840

Here the 30% rule is the binding limit — your cashflow could stretch further, but the guideline keeps you comfortable at a 30% rent-to-income ratio. If your commitments rose to 2,000, the cashflow ceiling would fall to 520 and become the binding limit instead, pulling the recommendation well below the percentage rule.

Input	Recommended max rent	Binding ceiling
2,800 income, 30% rule, 1,000 expenses	840	30% rule
2,800 income, 35% rule, 1,000 expenses	980	35% rule
2,800 income, 30% rule, 2,000 expenses	520	cashflow

Note on the formula: the recommendation is min(income × rule%, income − expenses − savings). Every number is calculated in your browser — nothing is uploaded or stored.